Control device



NOV. 26, 1946. C, 5 KELLEY l 2,411,748

' CONTROL DEVICE Filed May 20, 1944 IN VENTOR BY @im ATTORNEY Patented Nov. `26, 1946 CONTROL DEVICE rCecil S. Kelley, Forest Hills, Pa., -asslgnor to The Westinghouse Air Brake Company, Wilmerdlng, Pa., a corporation` of Pennsylvania Application May 20, 1944, Serial No. 536,487

A 1 4 v This invention relates vto control devices and more particularly to the fluid pressure controlled and operated type. L

One object of the invention is to provide an improved fluid pressure controlled and actuated device for adjusting any desired means such as an engine governor to control the speed or powe output of the engine.

A more speciiic` object of the invention is theprovlsion of such a device embodying a fluid pressure controlled power piston and valve means arranged for control by fluid under pressure for controlling the pressure of fluid on the power piston. r

Still another object of the invention is the provision of a device of the above general type embodying a power piston and a multiplicity of ilexible diaphragms all of which are arranged in coaxial relation providing aV relatively small compact and efllcient structure.

Other objects and advantages will be apparent from the following more detailed description Yof the invention. n

In the accompanying drawing; Fig, 1 is a longitudinal view, mainly in section, of the improved device; Figs. 2 to 5 are sectional views taken on lines 2-2, 3-3, 4-4 and 5 5', respectively, in Fig. 1, Figs. 2 and 3 being shown on an enlarged scale; and Fig, 6 is a line diagram of a portion of the structure shown in Figs. 1, 4 and 5.

feet or lugs 2.` One end of the cylinder I is closed by an integrally formed non-pressure head 4,

' while the opposite end isclosed by a removable pressure head 5. A pile or stack of substantially ring like casing sectionsl, 1 and 8 are secured to each other and to the non-pressure head 4 in coaxial relation to cylinder I. The casing section 3 at one end of the pile is mounted against the end of the cylinder, while secured to casing section 8, disposed at the opposite end of the pile, is a cover 9. v

A power piston I is slidably mounted in the cyl'- inder I. Cla'mpedaround its peripheral edge between the end of cylinder I and one side of casing section 8 is a iiexible diaphragm II. Two oppositely arranged flexible` diaphragms I2 and I3 are clamped, around their edges, between, respectively, the adjacent faces of casing sections 6 and 1, and 'I and 8. In the opposite face of casing section 3 is a recess in which are disposed the peripherlal edges of two exible diaphragms I4 and I5 and a spacer ring I8 separating said diaphragme from each other. The cover 9 has a ring like extension Il projecting into the recess and engaging the edge portion of the adjacent diaphragm I5, whereby the diaphragms I4 and I5 are securely e claims. (ci. A12x- 41) clamped 'between the casln'g section 8 and cover .9. All of these diaphragms are arranged in coaxial relation with each otherand with the power piston I0. The flexing portions of diaphragms Il.

I 2 and I3 are of the same areas. The flexing portions of diaphragms I4 and I3 are each of a lesser area and their areas are equal to each other.

Between the power piston I0 and non-pressure head 4 is a non-pressure chamber 20 which is open to atmosphere through a passage 2l, while between said piston and pressure head 5 is a power pressure chamber 22 which is open to a fluid pressure control passage 23. A rod 24 extending through piston I0 and secured thereto passes through pressure chamber 22 and a suitable bore in thel pressurehead 6 to beyond theouter surface thereof. The pressure head 5 is provided with two recesses spaced from each other and encircling the piston rod 24, and in each of these recesses there is disposed a sealing ring 25 providing a sea1 between the pressure head and said rod to prevent leakage of fluid under pressure Vfrom chamber 22 along said rod to atmosphere. A lubricating fitting 23 is secured to the pressure head 3v and is open to a lubricating recess 21 provided in said head around the piston rod whereby the portion of said rod which slides through said head may be lubricated as required.

v. The piston rod 24 projects slightly beyond the rear face of piston I0 into non-pressure chamber 20. wherein it is provided with a spherical like end 3| which fits in a recess provided at the center of one side of a spring seat or follower 28. A like follower 29 is oppositely arranged adjacent the non-pressure head 4 and extending between and having contact at its opposite ends with these two followers is a coil control spring 30. This spring is confined between the two followers under pressure for urging said piston in the direction of the left hand upon release of fluid under pressure from chamber 22 and for opposingumovement of said piston in the opposite direction upon supply of fluid under pressure to chamber 22. The extreme left hand position of piston I0 is determined by contact of said piston with a stop 32 provided on the pressure head 5.

Between non-pressure head 4 and diaphragm II is a chamber 35 which is openthrough a passage 33 `to non-pressure chamber 20. Between the two diaphragms II and I2 is a chamber 31 to which is connected passage 23 leading from the pressure chamber 22.- A diaphragm follower 38 disposed in chamber 35 in coaxial relation with diaphragm II has one side in contact with the adjacent surface of said diaphragm and is provided on its opposite `side with a plurality of raised stops 39 for contact with the adjacent side of the non-pressure head 4.` The non-pressure head 4 is provided centrally with 'a' bore which is lined with" a bushing 40 and slidably mounted in this bushing are 'three sectors of a ring like projection 4I of the follower 38. said and the adjacent spring follower 29 are al1 movable as a unit.

sectors being equally spaced from each other. A

drical like 4head 44 disposed in the recess in.

follower 28 for supporting said follower. It will be noted that follower 38 and member 42 are capable of movement in either direction in bushing 40. The bushingv 48 is kprovided in the nonpressure chamber 28 with an outturned collar 45 which is disposed in contact with the inner' surface of the non-pressure head. This collaris arranged for contact with member 42 to limit movement of the member in one direction.

The diaphragm follower 38 has a hollow projection 48 extending centrally therefrom through an axial opening in diaphragm Il into chamber 31, and disposed in this chamber and mounted over said projection against the adjacent face of diaphragm I I is a follower plate 49.

v A combined spacer and follower 50 is disposed in a chamber I formed between the two diaphragms I2 and I3 and has its opposite faces in contact with the adjacent faces of said diaphragms. The follower 50 has a sleeve like member 52 projecting centrally from one side through anv axial opening in diaphragm I2 into chamber 31, and slidably mounted on this member in said chamber is a sleeve 53 one end of which contacts the follower plate 49 which is in contact with diaphragm II. At the opposite end of sleeve 53 is a follower plate 54 which contacts the adjacent face of diaphragm I2. 'Ihe projection 48 of follower 38 is provided with external screw-threads, while the sleeve 52 encircling said projection has internal screw-threads cooperating with those on said projection. Turning of the follower 50 and sleeve 52 relative to and onto the projection 48 of follower 38 will therefore clamp the central portions of the two diaphragms II and I2 between their respective followers and secure such parts together for movement in unison.

Between the cover 9 and diaphragm I5 is a v Chamber 5| between diaphragms 'I and I3 is connected to a pipe 65 adapted to be supplied-- with fluid under pressure from any suitable source. Chamber 60 between the diaphragms I3 and I4 is adapted to be connectedto an' adjustment modifying pipe or what may be called a Vernier control pipe 66. Between diaphragms I4 and I5 is a chamber 81 which is in constant communication with chamber 5I in a manner which will be later described.

The follower plate 58 has an axial projection 69 extending through control chamber 56 and with its end disposed toslide in a guide bore in a cap 10 removably secured by cooperating screwthreads to the cover-9. Encircling the projection 69 is a coil balance spring 1I, one end of which bears against the plate 58. The opposite end of spring 1I is supported on one or more shims 12 carried in the cap 10.

Within sleeve 59 is a chamber 15 which is open I through one or more radial bores 16 in said pressure chamber 56 which is open to a control pipe 51, and which contains' a follower plate 58 engaging the adjacent side of said diaphragm. This plate constitutes a ange provided at one end of a sleeve 59 which extends through central openings provided in the diaphragms I5 and I4, and in ring like spacer means 64 interposed between and engaging adjacent faces of said diaphragms, said sleeve extending into a chamber formed between the two diaphragms I3 and I4. The follower 50 arranged between diaphragms I2 and I3 has a hollow boss 6I extending through a central opening in diaphragm I3 into chamber 60 wherein said boss is provided with external screw-threads cooperating with internal screw-threads provided in sleeve 59. Slidably mounted on sleeve 59 within chamber 60 is a member having at one end a follower plate 62 contacting diaphragm I3 and having at the 0D- posite end a follower plate 63 contacting diaphragm I4. By tightening sleeve 59 on boss 6|, the central portion of diaphragm I3 will be clamped between followersv50 and 62, and the central portions of diaphragms I4 and I5 will be respectively clamped between follower 63 and spacer means 65, and said spacer means and plate 58. With the parts assembled in the manner'so far described-it will be noted that the central portions of all of the diaphragms, the stop 42 sleeve and aligned radial bores 11 in spacer means 84 to chamber 61. The boss 6I has an axial bore 18 open at one end to chamber115, while its opposite end is open through a seat, provided for engagement by a supply' valve 19, to a chamber provided in member 52. At the end adjacent the supply valve 19, the bore 18 is open through one or more radial bores 8| to the fluid pressure supply chamber 5I.

The supply valve 19 is provided on one end of a stem 82 extending through bore 18 into chamber 15 and said stem is provided with a plurality of longitudinally extending spaced ribs 83 having sliding contact with the wall of said bore, said ribs terminating short of said valve a distance equal at least to the width of the radial port 8l. In chamber 15 the valve stem 82 is provided with an enlarged head 84 which is engaged by one end of a coil spring 85. The opposite end of this spring seats on the end wall of said chamber, which spring is constantly effective to urge the supply valve 19 toward its seat with a relatively light degree of force.

The projection 48 of follower 38 is provided with an axial bore open at one end to chamber 80, and slidably mounted in this bore and extending into said chamber is a plunger 81. The plunger has a stem 88 extending through a bore provided in follower 38 into the space within the projection 4I.. .The end of stem 88, within the projection 4I, is supported on a member 89 having radiating fingers 90 extending through the spaces between the sectors of projection 4I and supported on a suitable annular shelf 9| provided on the non-pressure head 4.

The stem 88 is provided with an axial bore 92 open at the end adjacent support member 89 to a plurality of radial bores 93 leading to the space within the projection 4I which space is open to atmosphere through the space between the sectors of said projection and thence by way of nonpressure chamber 20 and passage 2|. The opposite end of bore 92 is opened to the interior of The release valve pin 95 extends into chamber` 80 and therein is provided with a head |00, and between this head and the adjacent end of plunger 81 is interposed a coil spring I0| which constantly tends to urge the release valve 94 away from its seat. The supply valve 19 is provided with a stem |02 loosely extending through the seat for said valve and engaging the head which is at all times maintained in contactwith said stem by spring IOI, whereby the supply valve 19 and release valve 94 will move in unison.

Projecting from' pressure head 5 is a bracket and connected to said bracket by a pin |06 is one end of a rockable link |01. The other end of link I 87 is disposed between outer ends of two arms |08 of a lever |09 and is rockably connected thereto by a pin IIO. The two arms |08 are integrally connected intermediate their ends by a. bridge I I I. Disposed between the opposite ends of the two arms |08 are jaws I |2l provided onone end of a member |I3 which is provided for connecting the device to the means to be operated, such as an engine governor. The piston rod 24 has a tongue II4 disposed between the jaws II2.

The Irlston rod 24 is connected to the member I|3 and the ends of the lever arms |08 by a pivot pin I|5 having an axial portion I5 at one end extending through and operatively connecting one of the lever arms I 08to theadjacent jaw I I2. The pivot pin |I5 has another axial portion II1 extending through and operatively connecting the other lever arm |08 to the jaw, and the two axial portions ||6 and I|1 are connected by a part in the form ofan eccentric I|8 which extends through and operatively connects the piston rod 24 to the pivot pin I I5 and thereby to member II3. The eccentric IIO bears in the tongue II4 of the pistonrod against a bushing II9 provided in said rod.

The axial portion |I1 of the pivot pin ||5 is of greater diameter than the axial portion I I6 and bears at its inner end against the adjacent face of the piston rod tongue II4. On the outer end of the axial portion |I1 is an adjusting disc |20 bearing against the adjacent Vlever arm |08.

'I'his disc is provided across its outer face with a screw driver slot |2I for turning the disc and pin I|5 relative to the piston rod 24 and other connected parts. The disc |20 also has a semicircular through slot |22 adjacent its peripherlal edge through which extends a stud I 23 secured in the adjacent lever arm |08. A nut |24'on stud I 23 is provided for securing the disc |20 and thereby the pivot'pin I5 to the adjacent lever arm |08 for movement therewith. Loosening of nut |24 providesfor adjustment of the pivot pin ||5 relative to the lever |09 and member ||3 and thereby angular adjustment of eccentric I8 relative to the end ofthe piston rod 24.

The adjustingslot |22 is so arranged in the disc |20 that with the disc secured in a position with the stud |23 at the center of slot |22, a line intersecting the axes of the pivot pin ||5 and eccentric |I3 rwill be vertical to a line intersecting the axes of the pivot pin and of-pin |I0 at the opposite end of lever |09. Adjustment of the pivot pin ||5 by turning disc |20 in a counterclockwise direction,V as viewed in Fig. 1, willincrease the distance between theicenter of the eccentric and pin ||0 and thereby increase the length of the lever arm for the piston rod 24, while adjustment in a clockwise direction will brought out.

v piston rod 24.

|09 or member ||3, but only the connection between the piston rod 24 and the pin II5. These facts are believed to be clearlybrought out in the line diagram in Fig. 6 wherein the pivot pin is indicated by the portion IIB thereof and to the center of this portion are connected lines indicating the lever |09 and member I|3. The eccentric II8 is shown in the neutral position occupied with the adjustment of disc |20 as in Fig. 1 and above described, and connected to the center of the eccentric is a line indicating the The purpose of this structure Including the eccentric II8 will be hereinafter Operation In operation, let it be assumed that member ||3 is connected to the device which it is desired to operate or adjust. Let it further be assumed that the fluid pressure supply pipe 851s connected to a suitable source of uid under pressure; that the control pipe 51 is connected to a suitable operator's control valve device, and that the vernier controlpipe 68 is connected to a suitable operators vernier controlvalve device.

With pipe 65 supplied with fluid under pressure from the source, fluid under pressure will equalize into chamber 5| between the two diaphragms I2 and I3 and thence past the ribs 83 on the supply valve stem 82 into chamberv 15 and from chamber 15 through bores 16 and 11 into chamber 61 between the diaphragms I4 and I5. The pressure 'of fluid in chamber 5I acting on diaphragm I2 counteracts said pressure acting on diaphragm I3, and vice versa, and the same is true with respect to said pressure in chamber 81 acting on the diaphragms I4 and I5, so that such pressure will have no effect upon operation or positioning ofthe structure longitudinally of the device.

It is intended that by operation of the operators Vernier control valve device fluid at a chosen nominal pressure, such as twenty-five pounds, will normally be provided through pipe 96 in chamber 60 between the two diaphragms I3 and I4, and since the diaphragm I3 is of greater diameter than diaphragm I4, this pressure will create a force acting v,inthe direction of the left hand, asviewed in the drawing, equal to the pressure of such fluid times the difference in areas of the two diaphragms. l

The minimum pressure normally provided through control pipe 51 in chamber 58 to act on diaphragm I5 is preferably of a chosen low degree, such as five pounds, and in use, the operators control valve device is intended to vary the pressure of iluid in chamber 56 only between this low pressure and a selected higher pressure such as fifty pounds. It will be noted that this pressure effective on diaphragm I5 also creates a force urging the parts of the device in the direction of the left hand. The pressure of spring 1| also acts on diaphragm I5 in the same direction.

The pressure of spring 1| is so adjusted by shims 12 that its force plus the minimum pressure of fluid (five pounds) acting in chamber 56 on diaphragm I5, plus the force created by the normal pressure (twenty-five pounds) of fluid in chamber 60 acting on the differential areas of diaphragms I3 and I4 will, with the parts of the device in the positions shown in the drawing, just balance the opposing force of control spring 30 applied through stop 42 to the followers, spacers,

sleeves, etc. connecting the central portions of the several diaphragms together. With the parts of the device positioned as shown in the drawing, the stop flange 43 of the strut member 42 is slightly spaced away from stop collar 45 carried by the non-pressure head l of cylinder I, permitting the plunger 81 to be positioned with respect to the member 89, which is fixed with respect to the casing, S that the supply valve 19 will be closed by spring 85 and the release valve 94 will also be closed by said spring acting through the supply valve and the stem |02 proiecting therefrom and contacting the release valve. Under this condition pressure in chamber 31 and pressure chamber 22 will beat such a low degree, for reasons which will hereinafter be brought out, that piston l0 will be in contact with stop 32 and the operated member ||3 will be occupying the position shown in the drawing.

If the operator now desires to move the operated member ||3 in the direction of the right hand to 'effect an adjustment of the device being controlled, he will increase, through control pipe 51, the pressure of fluid in chamber 56 acting on the diaphragm i5. This increase in pressure of fluid will destroy the balance of forces above mentioned, and produce a force exceeding that of spring 30, as a result of which the central portions of the several diaphragms and the connecting sleeves, etc. will move in the direction of the left hand to a position limited by contact between stops 39 on follower 38 and the non-pressure head 4. This movement will be relative to the member 89 and plunger 81 which are supported by the casing against movement, and as a result the release valve 94 will remain stationary and act through pin 95 and its head |007 and stem |02 projecting from the supply valve 19 to hold said supply valve against movement, so that the seat for the supply valve will move out of contact therewith. Fluid under pressure will then flow from chamber 5| past the supply valve 19 to chamber 80 and thence to chamber 31 between the two diaphragms I and I2 and from the latter chamber through passage 23 to pressure chamber 22. Since the diaphragms and l2 are of equal areas, the pressure of fluid obtained in chamber 31 and acting on either diaphragm in one direction is counterbalanced by its opposing effect on the other diaphragm, as will be apparent.

When the pressure of fiuid thus provided in pressure chamber 22 is increased sufllciently to overcome the opposing force of spring 30 on piston I0, said piston will move away from stop 32 against the opposing pressure of spring 30 and L thereby act through the rod 24 to draw the member ||3 toward the right hand towards its new position.

The piston I0 as it is being moved under the pressure of fluid provided in chamber 22, will act to compress spring 30 and thus increase the spring force applied through follower 29 and stop 42 to the central portions of the diaphragms. When this force is increased to a degree substantially equaling the increase in the opposing force created by the increase in pressure of fluid in diaphragm chamber 56, said spring will act to move strut member 42, the central portions of the diaphragms and the connecting sleeves back in the direction of the right hand, This movement will be relative to plunger 81 and to the release valve 94 and supply valve 19 which are at this time supported by said plunger, and will continue until the seat for the supply valve moves into contact with said supply valve. The supply of fluid under-.pressure to pressure chamber 22 will thus be cut of! when it is increased to a degree for sumcientiy increasing the pressure of spring 3l to offset the increase in pressure of fluid in the control chamber Il, andto thus 4restore the balance of opposing forces, 'above mentioned. 1

It will now be seen that the piston I0 will be moved away from -the stop 82 a distancev correspondingI to the pressure of fluid provided in chamber 22, and thus corresponding .to the increase in pressure of fluid in control chamber 56, and it will be further noted that the operated member ||3 and device being controlled will be also adjusted to correspond.

If the operator desires to cause the member ||3 to move further in the direction of the right hand, he will increase the pressure of fluid in chamber 56 thereby again destroying the balance of opposing forces, and the structure will then operate in the same manner as above described to cause a corresponding new adjustment of member II3. Within the limits of :the device, the memberl H3 can thus be caused to move from the position shown in the drawing to any selected position to the right -hand side thereof, and such movement may be effected in any desired steps, by providing in the control chamber 55 fluid at the proper selected pressures.

Withthe member H3 adjusted out of its normal position in the direction of the right hand,

if the operator should desire to cause said member to move back toward the position in which it is shown in the drawing, he will reduce the pressure of fluid in chamber-55, whereupon the force of spring 30 will exceed the opposing forces and acting through strut member 42 will shift the diaphragms and supply valve 19 in the direction of the right hand from the positions shown in the drawing. Due to the yaction of spring |0|, the release valve 94 will move with the supply valve and thus be shifted out of seating engagement with the plunger 81 which will be held by spring |0| in contact with member 89 and thus against movement. When the release valve 94 is thus opened, fluid under pressure will then be released from pressure chamber 22 through passage 23, chambers 31 and 80, spaces '98, recess 99, passages 92 and 93 in the plunger stem 88 -and thence to atmosphere.

As the pressure of fluid in pressure chamber 22 is thus reduced, the spring 30 will expand and move the piston l0 back toward its normal position, and a reduction in the force of said spring against the diaphragms will occur. Assuming that the pressure in control chamber 56-is not reduced to its normal value (ve pounds) then when the pressure of fluid in pressure chamber 22, and consequently -the pressure of spring 30 has become reduced to substantially the same degree as the opposing forces including the reduced pressure of fluid in chamber 56, said opposing forces will gradually shift the diaphragme and both the supply -and release valves toward the left hand. and at the time the balance between opposing forces is obtained, the release valve 94 will engage its seat and thus prevent further release of fluid under pressure from chamber 22. Thus the reduction in pressure of fluid in chamber 22 will be limited in proportion to the reduction in control pressure in chamber 56, and the piston 0 will therefore move the member l|3 to a corresponding position.

In case the operator effects a further reduction in the pressure of fluid in chamber 56 the structure will again operate as just described to eiect a corresponding further reduction in pressure in chamber 22 anda corresponding change in position of piston 22 and of member II3. The member I I3 m`ay be thus caused to return toward its normal position in any desired steps as selected bythe degrees of reduction in pressure ofv fluid in chamber 56.'

In case the pressure of iluid in chamber 56 is reduced to its normal minimum value of five pounds, the structure will again operate in the same manner as above described to open the release valve 94 and permit further release of tluid under pressure from piston chamber 22. Under the action of spring 30, the piston III will then move back into contact with stop 32, permitting the pressure of said spring to reduce to its normal value.v As the force of spring 30 is thereby reduced, the normal pressure of fluid in chamber 56 plus the pressure of spring 'II will return the diaphragms to their normal positions and seat the release valve 94 at substantially the time the piston contacts stop 32, thereby bottling' the remaining uid in chamber 22, which pressure may be near atmospheric pressure or of a greater degree, depending upon the coniined force of spring 30. This is however immaterial, since the return of piston I to its normal position upon reducing the pressure of iiuid in the control pipe 51 to the normal value will cause return of the member II3 to its normal position, as will be apparent. It will now be seen that the member II3 may be adjusted out of normal position to any selected position or in the reverse direction to any selected position, or may be returned to normal position by providing fluid at the proper selected pressure or pressures in chambel! 56.

If the member II3 cannot be adjusted with a suiiicient degree of accuracy by varying the pressure in chamber 56, then after, what may be termed a rough adjustment in response to a selected pressure change in said chamber, the operator may eil'ect s, fine adjustment of said member by effecting through pipe 66 a change in pressure in the vemier control chamber 60. An increase in pressure of uid in chamber 60 Will increase the force opposing spring 30, while a reduction in pressure of fluid in chamber 60 will reduce the force opposing spring 30, and the device will operate in response to such increase or decrease in pressure of fluid in chamber 60 to' eiect a proportional change in position of member II3 in either one direction or in the opposite direction in the same manner as before described. It is desired to point out that for a certain change in pressure of fluid in chamber 60 the change in force is only a fraction of that resulting from a like change in pressure of fluid in the main control chamber 56, due to the diaphragm I5 being of greater area than the difference in areas of diaphragms I3 and I4. Hence a iiner change in force and adjustment of member II3 may be effected by varying pressure of fluidL in chamber 60.

`This iine or vemier control of adjustment of member I I3 is of particular value in for instance multiple engine installations where the speed or power output of all engines is arranged for control in unison from a master controller and it is desirable to match the output of the engines. In an installation embodying say two engines, both would be provided with a control devicesuch as shown in the drawing and the pressure chamber 56 in both devices would be connected to a com- Q I v mon operators control valve.

power of the two engines were not identical, the

operator 'by ,proper adjustment of pressure of fluid in chamber 60 of one of the control devices' could change the speed or output of the respective engine to the same degree or value as that of the other engine. I

In such an installation, the vernier'control of one engine might be suillcient to match the two engines. At the other engine, pipe 66 would not therefore be required and chamber 60 could be open to atmosphere with a consequent loss oi' force for opposing spring 30. This loss of force may however be compensated for by placing additional shims I2 under the spring II so that the device will operate in harmony with the other device having uid pressure in chamber 60.

In the manufacture of springs, such as spring 30, it is substantially impossible to produce on a commercial basis two springs having identical characteristics. Springs are therefore 'usually manufactured to certain limits, so that with respect to spring pick-'up a greater degree of deilection may be required to obtain a certain spring force withone spring than would be required with another spring, and as applied to spring 30, the one spring would allow greater movement of piston I0 away from stop 32 than would be permitted by the other spring with piston I0 subject to fluid at the same degrees of pressure. Stated in another way, with the maximum control pressure provided in diaphragm chamber 56, and in pressure chamber 22, a spring 30 with greater pick up would permit less total movement of piston I0 away from stop 32 than wouldl occur with a spring with less pick up. Consequently the total stroke of piston I Il will depend upon the pick up of the particular spring 30 employed, and in different devices or in the saine device in case spring 30 is changed; may therefore be either greater or less than the normal chosen stroke.

If the member II3 is connected to a member for controlling an engine governor which latter member has a xed range of movement to provide for varying of engine speed from minimum to maximum, lthen it is necessary to provide for adjustment of the connection between the member II3 and the piston rod 24 according to the pick up characteristic of the spring 30 so as to limit the range of movement of member II3 to the i'lxed .degree in case the stroke of piston III as permitted by said spring is greater or less than said xed degree. This adjustment is accomplished by the means including the eccentric I I8. With the eccentric I I8 and adjusting disc I2II adjusted as shown in Figs. 6 and 1, respectively, the axis of the connection between the piston rod 24 and said eccentric will merely move from the position shown in Fig. 6 above the axis of the connection between member II3 and the pivot 4 vpin II5 o-r portion IIS thereof, to a corresponding position below, so that the movement of member I I3 will be the same 'as that of piston rod 24.

This adjustment of the eccentric will be employed ment of pi-ston l in excess of the required movement/ of member ||3. Lesser degrees of move-` ment of piston I0 in excess of the required movement of member I3 may be obtained by suitable adjustments of disc |20 between normal position and the position above mentioned defined by stud |23. Thus if the pick-up of spring 30 is less than normal, the proper adjustment of di-sc |20 counterclockwise from its normal position will match the movement of piston |0 to the fixed range of movement of member H3.

On the other hand, if the pick-up of spring 30 is greater than normal which would result in less movement of piston l0 than required of member ||3 the disc |20 may be turned from its nor- -mal position in a clockwise direction which will raise the axis of the connection between the piston rod 24 and eccentric to a point above the axis of the connection between member ||3 and the pivot pin I I5, so that the lever |09 will act to increase the movement of .member ||3 with respect to that of the piston rod. By suitable adjustment of disc |20 to the spring 30 the fixed degree of movement of member ||3 can therefore be obtained.

Thus regardless of the pick-up characteristic of the particular spring 30 used in the device, within the permissible limits of variations of said spring, adjustment of the eccentric ||8 to the particular spring will limit the range of movement of member ||3 to the desired fixed degree, or will provide for obtaining such fixed degree of movement, as the case may be.

After adjusting the eccentric it must be locked to lever |09 in the adjusted condition by tightening nut |24 against disc |20.

Summay A It will now be seen that Iv have provided a relatively simple, compact and eilcient device embodying a fluid motor and fluid pressure controlled means for controlling said motor. The structure is particularly applicable for control from a remote control station to provide prompt and accurate adjustments of a device to be controlled, and where the adjustments are within a given range, the operation of the structure may be regulated to meet the range regardless of permissible variations in the control spring.

Having now described by invention, what I clainii as new and desire to secure by Letters Paten s:

l. A fluid pressure control device comprising a casing, a control spring, a power piston in said casing subject to opposing pressures of said control spring and of fluid in a power chamber and adjustable to different positions corresponding to diierent pressures of fluid in said power chamber, valve means operable to supply and release fluid under pressure to and from said power chamber and subject to pressure of said control spring which is eiective to actuate said valve means to release fluid under pressure rfrom said power chamber, a movable member in said casing connected to said valve means and subject to pressure of fluid in a control chamber which opposes pressure oi' said control spring on said valve means and operable upon an increase in pressure of uid in said control chamber to actuate said valve means to supply fluid under pressure to said power chamber, and movable power means insaid casing connected to said valve means and subject to pressure of fluid in a third chamber which opposes pressure of said spring on said valve means.

2. A fluid pressure control device comprising a casing, a control spring, a powerpiston in said casing subject to opposing pressures of said spring and of fluid in a power chamber and adjustable to different positions corresponding to different pressures of fluid in said power chamber, valve means operable to supply and to release fluid under pressure to and from said power chamber, said spring acting on said valve means to actuate same relative to said piston for releasing fluid under pressure from said power chamber, a control movable member in said casing connected to said valve means and operable upon an increase in pressure of fluid in a control chamber above a normal degree to actuate said valve means against said spring to supply fluid under pressure to said power chamber, movable means in said casing connected to said valve means and subject to pressure of fluid in a third chamber which pressure in said third chamber coacts with pressure of uid in said control chamber acting on said control movable member, and spring means cooperabie with pressure of fluid effective on said control movable member 'and on said movable means to counterbalance pressure of said control Spring.

3. A fluid pressure control device comprising a casing, a control spring, a power piston in said casing subject to opposing pressures of said spring and of fluid in a power chamber and adjustable to different positions corresponding to different pressures of fluid in said power chamber, valve means operable to supply and to release fluid under pressure to and from said power chamber, said spring acting on said valve means to actuate samerelative to said piston for releasing fluid under pressure from said power chamber, a control diaphragm in said casing connected to said valve means and operable upon an increase in pressure of fluid in a control chamber above a normal degree to actuate said valve means against said spring to supply fluid under pressure to said power chamber, diaphragm means in said casing connected to said valve means and subject to pressure of fluid in a third'chamber which pressure in said third chamber coacts with pressure of fluid in said control chamber acting on said control diaphragm, and spring means cooperable with pressure of uid effective on said control diaphragm, and on said diaphragm means to counterbalance pressure of said control spring, said valve means comprising a poppet type supply valve and a poppet type release valve, and said power piston, said springs, and said control diaphragm and diaphragm means being all arranged in coaxial relation with said supply and release valves.

4. A fluid pressure control device comprising a casing, a control spring, a power piston in said casing subject to opposing pressures of said spring and of fluid in a power chamber and adjustable to different positions corresponding to different pressures of fluid in said power chamber. valve means in said casing operable to supply and to release fluid under pressure to and from said power chamber, said valve means comprising a poppet type supply valve, a poppet type release valve, means providing for movement of said valves in unison, a seat for said release valve fixed by said casing, a movable seat for said supply valve operable upon movement in one direction to first seat said release valve and then move out of seating engagement with said supply valve and operable upon movement in the opposite direction u into seating engagement with said supply valve,

meansioperable upon 'further movement of said I movable seat in said opposite direction to open said release valve, means for conducting uid under pressure to said supply valve for supply to said power chamber, said spring acting on 4said movable seat to urge same in-said opposite direction, a movable wmember in said casingconnected to said movable seat and subject to pressure of iluid in a control chamber and operable upon an increase in such pressure to move said seat in said one direction, a pair of flexible diaphragms in said casing connected to said seat and cooperating=to provide a' bias chamber normally charged with uid under pressure, one of said diaphragms being o i' greater area than the other and so arranged that the pressure of fluidin said bias chamber is effective to provide a force opposing pressure of said control spring, and spring means acting on said movable member in opposition to pressure of said control spring with a force which combined with pressure of fluid in said control 'chamber acting on said movable member and pressure of fluid in said bias chamber effective on 4the difference in areas of said diaphragms counterbalances the pressure of said control spring with4 said power chamber supplied with iluid 'at a pressure corresponding to pressure of iluid in said control chamber. e

5. A nuid pressure control device comprising a fluid in said chamber and comprising a supply` casing, a control spring, a power piston in said casing subject to pressure of said spring and to 'the opposing pressure of fluid in a power chamber and adjustable to diilerent positions corresponding to the pressure of such fluid, valve means in said-casing for controlling pressure of valve, a release valve, and a movable member operable upon movement in one direction to rst close said release valve and then open said supply valve to supply fluid under pressure to said power as said pair 'and arranged in coaxialV relation thereyvith, and connected to said movable memben-said'third diaphragm and theadjacent one of said pair'cooperating to form a chamber open to said power chamber and containin said release valve and arranged to` receive uid under pressure supplied by said supply valve, another pair oi exible diaphragms arranged at -the side y oi' thenrst named pair of diaphragms opposite said third'diaphragm and also connected to said movable member, the other pair of diaphragms being of smaller areas than the nrst named diaphragms and arranged in coaxial relation therewith and cooperating to form a chamber open to said fluid pressure supply chamber, the adjacent two of the nrst and last named pairs of control chamber in which pressure of uid a# adapted to be varied, 'and a balance spring in said control chamber acting on the adjacent diaphragm with a force which, cooperating with V pressure of fluid in said control chamber acting on the adjacent diaphragm plus pressure of uid in said bias chamber effective on the difference in areas of the respective diaphragms forming said bias chamber, counterbalances the pressure of said control spring on said power piston with both said release valve and supply valve closed.

6. A fluid pressure control device comprising ta casing, a control spring, a power piston in said casing subject to pressure of said spring and to the opposing pressure of fluid in a power chamber and adjustable to different positions corresponding to the pressure of such fluid, valve means in said casing .for controlling pressure of iluid in said chamber and comprising a supply valve, a release valve and a movable member operable upon movement inone direction torst close said release valveV and then open said supi ply valve to supply fluid under pressureto said chamber and operable upon movement in the -opposite direction to first close said supply valve and to then eiect opening of said release valve for releasing iiuid under pressure from said soA chamber, said spring acting on said movable member urging same in said opposite direction, apair of flexible diaphragms in said casing of the same areas and arranged in coaxial relation and connected to said movable member and cooperating to -form a -uid pressure supply chamber open to said supply valve and supplied with fluid under pressure, a third iiexible diaphragm 'in said casing of the same area as said-pair and arranged -in coaxial relation therewith and connected to said movable member, said third diaphragm and the adjacent one of said pair cooperating to form a chamber open to said power chamber and containing said release valve and arranged tore'ceive fluid under pressure supplied by said supply valve, another pair ofilexible dlaphragms in said casing arranged at the side of the nrst named pair of diaphragms opposite said third diaphragm and also connected to said movable member, the other pair of diaphragms being of smaller areas than the first named diaphragms and arranged in coaxial relation therewith and cooperating to form a chamber open to said iluid.

pressure supply chamber, the adjacent two of theflrst and last named pairs oi' diaphragms cooperating to form a bias pressure chamber, and thev outermostof the last `named pair of dia-v phragms having at its outer face a control chamber in which pressure of iluld is adapted to be varied, and a balance spring in said control diaphragms cooperating to iorm a bias pressure chamber, and the outermost of the last named patriot diaphragms having at it! outer im chamber acting on the adjacent diaphragm with la force which cooperating with pressureof uid in said control chamber acting on the adjacent diaphragm plus pressureof fluid. in said bias chamber en'ective on the difference in areas ofv :the respective diaphragms forming said bias chamber counterbalances -the pressure of said control spring on said power piston with both said'vrelease valve and .supply valveclosed, said lvalves being of the popnet type and said springs being of the coil type, and said valves. springs and power piston being all arranged in coaxial relation with saidv diaphragms.

y Om 8. KELLEY. 

